

L 1 M l C. *5 

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AN IMPORTANT DISCOVERY. 


GOLD 


IN AN 


AMORPHOUS AND CHEMICALLY COMBINED CONDI¬ 
TION IN NATURE. 


A Pa mphlet, 


CONTAINING 


A PAPER READ BEFORE THE POLYTECHNIC ASSOCIATION OF 

the academy of arts and sciences, in 

NEW YORK, MARCH 12, 1868, 


ON THE 


NATURE, PROPERTIES, AND RELATIONSHIP OF GOLD. 


ALSO, 


DESCRIPTION OF SEVERAL NEW PROCESSES 
FOR EXTRACTING THE PRECIOUS 
METALS FROM THEIR ORES. 


4 * 


BY PROF. A. L. FLEURY, 

OF NEW YORK. 


Price, 50 Cents. 


BOSTON: 

FRED. B. DAKIN, PRINTER 

50 B ROM FIELD St. 

1868. 



o 



































































AN IMPORTANT DISCOVERY. 


GOLD 

IN AN 

AMORPHOUS AND CHEMICALLY COMBINED CONDI¬ 
TION IN NATURE. 

A Pamphlet, 

CONTAINING 

A PAPER READ BEFORE THE POLYTECHNIC ASSOCIATION OF 
THE ACADEMY OF ARTS AND SCIENCES, IN 
NEW YORK, MARCH 12, 1868, 


ON THE 

NATURE, PROPERTIES, AND RELATIONSHIP OE GOLD. 


ALSO, 


DESCRIPTION OF SEVERAL NEW PROCESSES 
FOR EXTRACTING THE PRECIOUS 
METALS FROM THEIR ORES. 


BY PROF. A. L. FLEURY ,, 
* 7 

OF NEW YORK. 


Price, 5 0 Cents. 


■> > 

>»> 

BOSTON: 

FRED. B. DAKIN, PRINTER, 

50 Bromfield St. 

1868 . 







kN EXCHANGE 

for 3 06 





INTRODUCTION. 



In the following paper I have embodied my own ideas 
concerning the existence of Gold in Nature. The presence 
of Gold in an Allotropic, Amorphous, and Oxidizable 
condition, as also the existence of Gold as an Oxide Chemi¬ 
cally combined with Silicic Acid (this latter condition 
has long been suspected by Professor BischofF in Bonn. See 
Elements of Chemical and Physical Geology published by 
Cavendish Society, Yol. III. pages 534, 535), are subjects 
of the greatest interest, for they seem to throw light on the 
many discrepancies in our metallurgical processes, and ex¬ 
plain why it is, that every year twenty-five millions of dollars 
in Gold, are left in the tailings as refuse. 

We do in our laboratories, metallurgic, and manufacturing 
establishments nothing e&e but attempt to imitate Nature; 
we have succeeded in preparing artificially a vast number of 
chemical combinations of Gold with other elements, but still 
persist in denying to Nature the same privilege. We need 
only look and sea rch for truths in the great book of Nature , 
and we will find them ; our test-books should be our guides , 
but not be our infallible Precepts. 

What a sneer would a man have provoked among our 
learned geologists had he, only a few years back, instituted a 
search for Gold in the Pennsylvania oil region! and still, 
Gold has been discovered there and in many places where 
Science denied its existence. 

That gold existed in Pyrites and other Sulphurets has been 
known for many years, but who suspected that a large por- 



IV 


INTRODUCTION. 


tion of Gold would pass off with the Sulphur and acid va¬ 
pors when the ores are roasted ? 

Why do our chemists find hundreds of dollars of Gold per 
ton in ores which, when worked at the mill, do not pay the 
expense of mining ? 

There is no doubt there have been many swindles perpe¬ 
trated upon the public, during the last Gold mania, but I 
feel satisfied in my mind that many ores that are now 
deemed worthless will enrich some men beyond their own 
expectations. 


G OLD; 


ITS HISTORY, NATURE, RELATIONSHIP TO OTHER ELEMENTS, AND 
THE BEST KNOWN METHODS OE EXTRACTION. 


A PAPER READ BEFORE THE POLYTECHNIC ASSOCIATION OF THE ACADEMY OF 
ARTS AND SCIENCES IN NEW YORK, THURSDAY, MARCH 12, 1868. By Prof. 
A. L. Fleury, of New York. 


What a history of joys and sorrows, of expectations and 
disappointments, of virtue and vice, of folly, passion, and 
crime, could many a small Gold dollar, or ducat, relate, were 
it gifted with intelligence and speech! What curious hid¬ 
ing-places and scenes could many an old Gold coin describe! 

However interesting and instructive as such a history of 
Gold among men would be, it is not the one I propose to bring 
before you this evening ; it is the History of Gold in Nature 
I contemplate to lay before you. We will trace the pre¬ 
cious metal to its rocky hiding-places, and attempt to unravel 
some of the mystery that seems to enshroud it; we will then 
give a brief account of its physical and chemical properties, 
then review its peculiar relationship to other elementary 
substances, and finally state some of the most effective and 
successful processes for its extraction from the various ores. 

Please give me your undivided attention, and I hope to be 
able to interest you. 

All modern accounts agree in tracing the origin of Gold to 
veins of quartzose and schistose character. Wherever Gold, 




G 


is found, either in the. sand of rivers, or in diluvial deposits, or 
in rocks, we ever find it enshrined, or, at least, in close prox¬ 
imity to Silica, either as Quartz, or as Clay Slate, or as an¬ 
other more complex siliceous combination. There are some 
exceptions, however, but these are few in number. 

Gold, in varying proportion, is found in most of the metallic 
Sulphurets, Arseniurets, and other similar compounds, either 
combined or free; but these are mostly embedded in quart- 
zose veins, or disseminated in schistose rocks. 

In order to understand more fully why Gold is found in the 
Sulphurets and other analogous combinations, and these again 
are enclosed in Quartz veins, we must trace out the Origin of 
Quartz itself. 

We have here several pieces of Quartz ; they all contain vari¬ 
ous metallic sulphurets, and some show traces of free Gold, 
all of which are firmly embedded in the crystalline siliceous 
mass. How did the Sulphurets and the Gold get into the 
Quartz, and what agency forced the Quartz through the fis¬ 
sures of the rocks ? 

We all know that Quartz is a product of aqueous and not 
igneous origin. We have ample proofs to that effect in the 
presence of volatile metals, such as Antimony, Arsenic, Zinc, 
and others, also in the presence of water in geods, and the 

4 

close proximity to hydrated and carbonated minerals. The 
theory of the injection of Quartz as a glassy, highly-heated 
mass, by volcanic agency, has been superseded by the more 
sensible one of aqueous action. 

The following thoughts I read last fall before the Asso¬ 
ciation of Natural History in Boston, and as they received 
the attention of most of its scientific members, I will state 
them here in as few words as possible. 

Reading the clear and beautiful explanation given by Prof. 
Frerny, in Paris, of the origin of the Gayser springs, and study- 


I 


i 

ing over his experiments with Bisulphide of Carbon on Silica 
Alumina, etc., I could not help coming to the conclusion that 
nearly all Quartz in nature owes its existence to the decom- 
p osition of Sulphide of Silicium by ivater. 

To make this idea clear, I must digress a little, and state 
my own views on the condition of the interior of our 
globe. 

Firstly, I believe in the existence of intense heat in the 
centre of our globe, — a heat of such intensity, that all the 
elements are thereby kept in an incandescent gaseous condi¬ 
tion. 

Around the gaseous commingled matter I conceive, at first, 
a very liquid, melted mass, attached to a half solid, somewhat 
plastic crust, which, as it gets farther from the centre, cools, 
and in its effort of expanding, breaks into fragments. The 
crust of our earth (probably forty miles in thickness), I con¬ 
ceive full of crevices and immense caverns, some of which, by 
passages of various dimensions, communicate with each 
other, and are ever changing, according to outward radiation 
of heat, condensation, and cooling of matter. 

For the sake of illustration, I will call Granite a primary rock , 
though I think that many rocks of by far greater age than 
Granite exist below, which to our surface rocks compare as our 
soil does to our own rocks. 

When Granite, or any other compound or simple Silicate, 
is, while under pressure and a bright red heat, exposed to 
vapors of Carbon and Sulphur (both of which exist in abun¬ 
dance in the interior of our earth), the Silica is decomposed: 
— the Oxygen of the Silica combines with the Carbon and 
forms Carbonic Oxide and Carbonic Acid, while the Sulphur 
seizes upon the Silicium and forms Sulphide of Silicium , a 
white earthy mass, withstanding a great degree of heat. 

As the interior crust of our earth is continually acted upon 


k 


8 

by cosmic disturbances, either by the gravitation of our own 
terrestrial substance, or by solar, lunar, or planetary influences, 
a gradual or sudden condensation, cooling, and breaking of the 
harder portion of the rocks takes place ; water rushes into the 
crevices, and, reaching the Sulphide of Silicium and other Sul¬ 
phides, is instantly decomposed in its turn by the Sulphide of 
Silicium into Oxygen and Hydrogen. Sulphuretted Hydro¬ 
gen Gas and a Hydrate of Silica are formed, both of which are 
soluble in water, and easily carried along by steam. The upper 
cavities, mostly filled with water impregnated with Carbonic 
Acid, which in itself is a great solvent and combining medium 
for metallic oxides, such as Iron, Copper, and others (all of 
which, no doubt, exist dissolved in this water), are suddenly 
broken into by these water vapors, carrying the hydrated Silica 
and Sulphuretted Hydrogen with them, and the Oxides, Hy¬ 
drates, and other metallic solutions are broken up; the Sulphur 
of the Sulphuretted Hydrogen seizes upon the metals, forms 
therewith Sulphides, and the whole mass is forced upward, 
together with the liquid Quartz. The hydrated Silica, car¬ 
rying the heavier Sulphuretted metals in the centre, comes in 
contact with the cool atmosphere and the cold sides of the 
crevices, and a Gelatinization and gradual Crystallization 
takes place, — the Sulphurets crystallizing in the Quartz. 

I can reproduce, artificially , in a small way, what nature 
has done on a large gigantic scale: — I can heat Granite to a 
white heat, expose it to the vapors of Bisulphide of Carbon, 
then treat the Sulphides resulting therefrom by steam, and 
cany the Hydrate of Silica and Sulphuretted Hydrogen into a 
basin containing Carbonate of Iron or other metallic solution, 
when the Silica will be seen to gelatinize slowly, and the Sul¬ 
phurets of Iron or Copper crystallize in the Silica. After this 
digression we will return to our chief subject, Gold. 

I believe that Gold is an elementary metallic substance like 


9 


Iron, Copper, Zinc, etc., and have no faith in the alchemistic 
idea of commuting baser metals into Gold, which idea, from 
time to time dives up here and there among the savans on 
the other side of the water. (Perhaps no better origin could 
be ascribed to the element Gold than that the President, rul¬ 
ing the regions below, has raffined his own favorite beverage, 
Brimstone , into Gold, and has presented it as a fit material 
for a golden calf to Moses and Aaron and our anxious Bulls 
and Bears of the gold-room.) 

Experiments which I have made in my o\yn laboratory 
have led me to the following original ideas: — 

1. That Gold exists in nature in two distinct allotropic 
conditions: In a metallic , molecular , crystalline state , with¬ 
standing the action of oxidizing agents under ordinary con¬ 
ditions, and in an amorphous , not metallic and oxidizable form. 
Plumbago and Lampblack may illustrate this idea. The for¬ 
mer, like metallic Gold, is heavy, a good conductor of elec¬ 
tricity, and has all the appearance of a metal, while the latter, 
the Lampblack, is easily oxidized, is light, is a non-conductor 
of electricity, and is amorphous. 

2. That in Sulphurets the Gold is mostly present in both 
modifications, and may sometime^ be found in a chemically 
combined state. 

I will here cite a curious experiment, which gives a fair 
illustration of what I say : — 

A quantity of finely pulverized Sulphurets from a rich mine 
in Colorado, Montana, or California is, at first, carefully 
treated in a close vessel, with Mercury-vapors, then cooled 
and washed, the Mercury separated, and the resulting quan¬ 
tity of Gold weighed. The Sulphurets, after having been thus 
treated, are then mixed with fine charcoal dust and Plum¬ 
bago, an equal quantity of each, placed into a carbon cruci¬ 
ble, and this into a porcelain retort, which has a tube at- 


2 


10 


tached, through which the gases that escape during the heat¬ 
ing of the crucible can be passed into a chlorine solution. 
When the crucible is slowly brought to a red heat, Bisulphide 
of Carbon issues forth, and at the same time the chlorine solu- 
tion darkens; when tested with Sulphate of Iron or Oxalic 
Acid, a precipitate of Gold is obtained. This volatilized 
Gold is not absorbed by Mercury. If the desulphurized re¬ 
maining ore is then again treated with Mercury-vapor, as 
before, cooled and washed, a third quantity of Gold is sepa¬ 
rated. 

This, and a number of other observations have brought me 
to think that Gold was, and still is, existing in nature in 
a chemically combined state , not only with Sulphur, but also 
with Silica as a Silicate of the Oxide of Gold Au O Si O 3 , as 
a Silicide of Gold Au Si, and, perhaps, in many other similar 
combinations. I ask you simply, my hearers : Did we ever look 
for Gold in a different state from the metallic ? We speak of 
invisible Gold, prepare in our laboratories solutions of Gold, 
Auric Oxides, Sulphides, and other combinations, and deny to 
natu/re, which we only imitate , the right and privilege to have 
used the same means, simply because our books say otherwise 
or nothing of it! Why carr we not oxidize Gold in its metallic 

state without first dissolving it ? I think it is simply for the 

* 

reason that it has to be brought to an atomic , amorphous state , 
and subdivision , before it is acted upon by Oxygen or Sulphur. 

Rose-colored Quartz is by miners considered quite a relia¬ 
ble indication that Gold may be expected at greater depth. 
By smelting glass with Purple of Cassius, Oxide of Gold, 
Auric Acid, or even finely divided precipitated Gold, we pro¬ 
duce a splendid crimson glass, which, if a smaller quantity is 
used, has the color of rose. If rose-colored Quartz is chemi¬ 
cally decomposed with Fluoride of Calcium, Gold can easily 
be detected in the result. I have witnessed many experi- 


11 


merits, *and made myself, while in Boston, a number of tests 
with various Fluorides, such as Cryolite, Fluorspar, and the 
so-called Stevens Flux, — all giving me the evidence that the 
opinion -expressed by Prof. Bischoff in Bonn, the best authority 
we have in chemical geology, that Gold, as well as Platinum, 
may derive its origin from the decomposition of Silicates, is 
well founded. 

We will now take up the next point, and give a brief ac¬ 
count of the 

Physical and Chemical Properties of Gold. 

Pure Gold is of a reddish yellow color, and possesses a high 
metallic lustre. In the pulverulent state it is brown and dull, 
but acquires metallic lustre by pressure. The specific gravity 
of melted Gold is 18.2, of hanAnered Gold, from 18.3 to 19.4. 
Finely divided Gold precipitated by Sulphate of Iron was 
found to vary in density from 19.55 to 19.72, and when pre¬ 
cipitated by Oxalic Acid, its density was 19.49. Its chemical 
equivalent of combination is 196.44, its formula Au., Aurum; 
its alchemistic sign, O or Sol, the Sun, the emblem of purity. 

In a pure state, Gold is softer than Silver, and nearly as 
soft as Lead, but its tenacity is so great that it may be drawn 
out into very fine wire. It is extremely malleable, and can be 
hammered out into leaves only ^n^oo °f an inch in thick¬ 
ness. The same amount of leaves (370,000) made of print¬ 
ing paper would reach nearly a hundred feet high! A single 
grain of gold may be extended over 57.75 square inches of 
surface, or drawn out into a wire 500 feet long. Reamur, by 
rolling out a fine Silver wire covered with Gold, reduced the 
coating of Gold to the twelve millionth of an inch in thick¬ 
ness, and the surface appeared to be perfect when viewed 
under the microscope. 

Gold does not directly combine with Oxygen, and therefore 
suffers no change by exposure to air and moisture at any tem- 


12 


perature, not even by being kept in a state of fusion In open 
vessels. 

I intend, so soon as I shall have sufficient time, to institute 
a series of experiments for the purpose of ascertaining the 
influence of the metalloids in vapor form on precipitated Gold 
under different degrees of heat, also how far electricity influ¬ 
ences its chemical character and stability. 

Gold, under ordinary circumstances, and in its metallic 
form is not attacked by the mineral, or any of the simple 
acids, except by Selenic Acid, with the aid of heat. To this 
must be added the interesting discovery of Prof. Henry Wurts, 
of this city, that Gold is soluble in Sesquichloride of Iron and 
Ferric solutions in general, — a fact that is of great importance, 
and deserves a most thorough investigation. The alkalies 
do not affect Gold. It is, under ordinary circumstances, not 
acted upon by Sulphur, and, therefore, Sulphuretted Hydro¬ 
gen is not decomposed by it, as is the case with Silver. 
Iodine has only a weak action upon it, but Bromine and 
Chlorine attack it easily at ordinary temperatures, and it is 
dissolved by any substance that liberates Chlorine. It is 
therefore dissolved by Hydrochloric Acid, if Binoxide of Man¬ 
ganese, Chromic Acid, etc., be added. The usual solvent is a 
mixture of one part of Nitric and four parts of Hydrochloric 

Acids. The proper solvent for Gold is nascent Chlorine, 

. • 

which is eliminated by the mutual action of the mixed acids. 

Gold is one of the most perfect conductors, both of heat 
and of electricity. It fuses at bright red heat, the tempera¬ 
ture of which has been estimated at 2016° F. It is, 
therefore, less fusible than either Silver (1873° F) or Cop¬ 
per (1996° F). In fusion it exhibits a bluish green color. 
Gold contracts on cooling, and cannot advantageously be 
employed for castings. Native Gold affords numerous 
well-defined crystals belonging to the cubic system ; and of 


1 Q 
lo 

• 

these the greater number is affected by the faces of the regu¬ 
lar octohedron. 

Gold has a peculiar metallic lustre, which, if once seen, can 
scarcely be mistaken. Its malleability and equally reflected 
light, when held at varying angles, distinguishes Gold from 
Pyrites and Sulphurets. 

The following are the chemical tests given by Muspratt: — 

Sulphate of Iron gives, in acid solution, a brown precipi¬ 
tate. If very dilute solution, only a blue coloring. 

Protochloride of Tin. In dilute solutions a purple red col¬ 
oring ; when strong, an almost brown precipitate. 

Metallic Zinc. Precipitates metallic Gold as a voluminous 
brown precipitate. 

Potassa in Excess. No precipitate; after some time a 
green coloring and slight precipitate. 

Ammonia. Yellow precipitate of Fulminate of Gold. 

Carbonate of Soda or Potassa. No precipitate in cold so¬ 
lutions, but when heated, voluminous precipitate, like Oxide 
of Iron. 

Bicarbonate of the same. No precipitate. 

_ • 

Carbonate of Ammonia. Behaves like Ammonia, Carbonic 
Acid being evolved. 

Oxalic Acid. Dark, greenish black precipitate, more 
quickly produced by heat. 

Tartaric Acid and Tartrate of Soda. Dark precipitate when 
boiled. 

Sulphide of Ammonium and Sulphuretted Hydrogen . Dark 
brown or black precipitate. 

The usual tests for Silver are the following: — 

Potassa. Brown precipitate ; becomes black on boiling. 

Carbonate of Soda or Potassa. White precipitate, soluble 
in excess of Ammonia. 


14 


Carbonate of Ammonia. White precipitate, soluble in 
excess of the same. 

Phosphate of Soda. Yellow precipitate, soluble in Am¬ 
monia. 

Oxalic Acid. In neutral solution a white precipitate. 

Sulphuretted Hydrogen and Sulphide of Ammonium. Black 
precipitate. 

Hydrochloric Acid. White, curdy precipitate, soluble in 
Ammonia. 

Zmc, or Copper. Precipitate, white metallic Silver. 

Sulphate of Iron. In neutral solutions white metallic Sil¬ 
ver. 

We will now rapidly glance over the series of Chemical 
combinations , which we have succeeded in preparing with 
Gold and other elements by artificial means. 

Aurous Oxide. Au O. Formed By precipitating Proto¬ 
chloride of Gold with a cold, dilute solution of Potassa. 
Blackish violet when moist, bluish violet when dry. This 
Oxide is permanent at ordinary temperatures, but decomposes 
at 250° C. 

Purple Oxide of Gold is formed, according to Berzelius, 
when a powerful electric current is passed through a thin 
Gold wire. The Gold burns with a green light, and is con¬ 
verted into vapor, which deposits itself on the adjacent 
surfaces in the form of Gold purple. This purple Oxide is 
formed even in air two hundred times rarified. The presence 
of other bodies favors the oxidation of Gold at high tempera¬ 
tures by predisposing affinity, — the oxide formed being gen¬ 
erally red. 

When Gold leaf is triturated with various substances, and 
exposed to the blowpipe flame on a small cupel, the following 
results are obtained: With Potassium: The alloy oxidizes 
quickly as it forms, and is converted into a black powder 


15 


which fuses into a violet glass with Silica and Borax. With 
Hydrate or Nitrate of Baryta: The Gold disappears and 
colors the Baryta red brown. With Hydrate of Lime : The 
Lime acquires a reddish or a bluish gray color. When Gold 
leaf is placed in a crucible with Hydrate of Lime, in alter¬ 
nate layers, and ignited, the Gold disappears and the Lime 
acquires a flesh color. 

With Silica containing Potash: Red coloring accompanied 
by disappearance of the Gold. With Zinc: Gray powder, the 
• gold disappearing. With Iron filings : The Gold disappears 
quickly, and yields a gray mass ; and if this substance be 
ignited with fresh Gold leaf, as long as the latter disappears, a 
red mass is obtained still having the form of the filings, and 
very slightly soluble in dilute Sulphuric Acid, the solution not 
being attended with evolution of gas (T. A.. Buchner Rep. 
27,1). It is in this red form that Gold enters into glass fluxes. 

Auric Acid , or Teroxide of Gold. Au O 3 produced by 
precipitating a hot aqueous solution of Terchloride of Gold, 
free from excess of hydrochloric acid, with a strong excess of 
Potash. There are many other methods of preparing it. It is 
a brown-black powder, having a conchoidal fracture. Decom¬ 
posed by light, or at an incipient red heat , into metallic Gold 
and Oxygen Gas; it gives up its Oxygen to vegetable acids, 
and many other substances. When boiled with Potash lye, 
it is resolved into Protoxide of Gold and Aurate of Potassa. 

Hydrated Auric Oxide , Au 0 3 -|-H0. This is obtained by 
mixing a solution of Terchloride of Gold, not containing free 
acid, with a quantity of Potash, only just sufficient to neutral¬ 
ize the Hydrochloric Acid, and repeatedly washing the reddish 
yellow precipitate, which does not appear till after the lapse 
of several hours. The Hydrate, after drying in the air, which 
takes place but slowly, exhibits a chestnut brown color. 
When heated to one hundred degrees C, or when treated with 



16 


Potash solution, it gives up its water, and is converted, with 
•. diminution of volume, into the black oxide, part of which, 
however, is reduced to the metallic state. This Hydrate is 
perfectly soluble in Hydrochloric Acid. 

Identical with this, appears the precipitate which Vanque- 
lin obtained, by heating the acid Gold solution with pure Pot¬ 
ash or Carbonate of Potassa. This precipitate when recently 
formed, was of loose texture, and of reddish-yellow color ; re¬ 
sembling, when deprived of its moisture, dried blood. With 
acids it forms the salts of Auric Oxide, or Auric Salts , and 
with the alkalies and some of the earths compounds called 
Aurates. 

Gmelin describes another very interesting combination 
with Oxygen. Per auric Acid. Au O 5 ; but this seems to be 
a mixture of oxides. 

Gold and Sulphur. Protosulphide of Gold Au S. A 
black-brown powder, exhibiting a deep yellow streak, is pro¬ 
duced by passing Sulphuretted Hydrogen through a boiling 
solution of Chloride of Gold. 

Persulphide of Gold Au S 3 . By precipitating a solution 
of Terchloride of Gold with Sulphuretted Hydrogen, or an 
alkaline Hydrosulphate at ordinary temperature, a black pre¬ 
cipitate results. According to Levol (N. Ann. Chim. Phys. 
30, 355) the precipitate thus formed consists of Au S 2 which 
contains water , and does not give it up till heated to 140° C. 
It is also prepared by fusing Gold in excess with Pentasul- 
phide of Potassium and dissolving the fused mass in water 
and precipitating by an acid. The Sulphide of Gold then 
falls down in deep yellow flakes which turn brown on drying. 
(Berzelius.) 

I will only quote a few more of the artificial Gold combi¬ 
nations, which of late have grown to a formidable number. 

Protochloride of Gold Au C. Yellowish ivhite, formed by 



% 




17 


heating Terchloride of Gold to the melting point of Tin, in a 
porcelain basin. Hydrogen Gas, passed for some time through 
a neutral solution of Chloride of Gold, gives a fine purple-red 
color without forming a precipitate. 

Terchloride of Gold Au Cl 3 . Gold leaf heated in chlo¬ 
rine Gas absorbs it without visible combustion. Gold leaves 
and finely divided Gold obtained by precipitation dissolves in 
heated Hydrochloric Acid. Gold dissolves, even at ordinary 
‘temperatures, in Chlorine water , in mixture of Nitric Acid with 
Hydrochloric Acid, Salammoniac, and common Salt, and in 
mixtures of Hydrochloric Acid with Nitrates or with Chromic 
Acid. 

Au + N O s + 3 H Cl= Au Cl» + 3 H O -f- N O 2 . 

It is very interesting to study the action of the various 
metals and other elements as well as compounds on the solu¬ 
tions of Terchloride of Gold. Some precipitate the Gold as 
yellow metallic Gold, some as a black powder, and some as 
the red oxide. In short, there is evidently a large field for 
research. 

I extract the following curious item from Graham’s Hand¬ 
book of Chemistry : — 

“ Gold and Silicium. Finely divided metallic Gold, Chloride 
of Gold, fulminating Gold, the precipitate thrown down from 
solution of the Chloride by Potash, or by Silicate of Potassa, 
the Purple of Cassius, etc., fused at a continued gentle heat, 
with a glass containing Oxide of Lead , impart to it, according 
to circumstances, a yellow or a purple-red color. Among the 
various explanations which have been suggested for the red 
coloring which has been imparted by heat to colorless auriferous 
glass, the most probable, according to H. Rose (Pogg. 72. 556), 
is that the colorless glass contains a Silicate of Aurous Oxide ) 
which requires a high temperature to produce it, and can bear 

3 


18 


that temperature without decomposition ; but that when it is 
heated to a lower temperature, part of the Aurous Oxide sep¬ 
arates out, and produces the color, and finally, at a stronger 
heat, the separate Aurous Oxide is reduced, and the glass 
thereby rendered liver-colored and opaque.“ 

It would take us too long were we to review even the most 
important combinations of Gold with other substances ; enough, 
however, can be seen from this, that there must exist similar 
combinations in nature ; we have only to look for them, and 
specially among the Silicates, the combinations of Gold with 
metalloids and easy volatile metals, such for instance as Gold 
and Arsenic, Bismuth, Antimony, all of which form alloys 
with it, and change the point of volatilization. 

For instance Arsenide of Gold, a gray brittle alloy, is easily 
fusible, and does not give up all its Arsenic even when fused 
for two hours in an open crucible. 

SPONGE GOLD. 

Du. C. T. Jackson, of Boston, discovered the manufacture 
of Sponge Gold, capable of welding while cold, by adding to 
a concentrated solution of Chloride of Gold a small quantity 
of Oxalic Acid, and then a sufficient quantity of Potash, or 
Carbonate of Potash, to dissolve nearly all the Oxide of Gold, 
and then adding a large quantity of crystallized Oxalic Acid, 
and boiling the solution. All the Gold is thrown down as 
a spongy mass, which, on being washed, is quite pure, and 
when pressed or hammered, becomes quite solid. — (Am. Jour. 
Science (2) 6-187.) 

The action of Electricity on different solutions of Gold is 
very interesting. Among other phenomena of less importance, 
1 will here mention that Electricity can be used for dissolving 
Gold in Salt water in presence of Peroxides. The Chloride 
oi Sodium is decomposed, and the Chlorine seizes upon the 


i 


19 


Gold and forms a soluble salt, while the Sodium oxidizes 
and forms Soda. At a future time I shall have occasion to 
say more on this interesting subject. 

Gold has been known from the earliest times ; the ancients 
called a native alloy of Gold and Silver u Electrum.” Vertru- 
vius and Pliny describe the amalgamation of Gold. The 
alchemists— Basil Valentine, for instance —were acquainted 
with the solution of Chloride of Gold, and with fulminating 
Gold; the latter compound has been more exactly investigated 
by Scheele, Bergman, Berzelius, and Dumas. Andreas Cas¬ 
sius and his son in 1865 described the preparation of Gold 
purple which was then adapted by Kunkel to the preparation 
of red glass, and afterwards in a variety of ways. Proust 
and Oberkampf discovered the Teroxide of Gold, and exam¬ 
ined many of the chemical characters of its Hydrochloric 
Acid solution ; the latter also discovered the Sulphide of Gold. 
Berzelius discovered the Protoxide and Protochloride ; Pel¬ 
letier, the Protoiodide, and the mode of preparing the pure 
Teroxide; Johnston, the Teriodide; Balard, the Bromide. 
Besides the Chloride of Gold and Potassium discovered by 
Javal, and the Chloride of Gold and Sodium discovered by 
Figuier, several other corresponding salts have been made 
known by Bonsdorff and Johnston. 

This is a shorf history of the Auro Family relationship. 

We will now take up the last point of our subject, the 
extraction of the Gold from the various ores, and the treat¬ 
ment of the tailings. 

The experience of the last five years (and a bitter experience 
indeed, it has been for many) has taught us a lesson; namely,, 
not to engage capital in a business before we understand it, 
practically as well as theoretically, at least in its most im¬ 
portant parts. 


20 


The manner in which gold-mining companies have been 
raised (quite an appropriate name for such an operation), 
during the Gold epidemic in this and other cities, is too well 
known to be here mentioned, and I will only draw a pencil 
sketch, describing one of the many offices, down town, where 
stock certificates of the many reported flourishing Colorado, 
Montana, and other Gold companies were sold to the poor 
pigeons who, attracted by the flattering and glowing report 
of an uninterested fashionable friend , called at one of these 
praised bowers of wealth. 

Imagine yourself stepping into a large, well-lighted, and 
splendidly furnished office on Broadway. You see several 
mahogany desks (such as Presidents only use), with soft 
cushioned arm-chairs for confidential chats placed beside them, 
and a large table, made of some expensive wood, in the 
centre. Heaps of glittering and sparkling ores (the so-called 
Fool’s Gold of the miners), Sulphurets of Iron, Copper, and 
Lead are, as if accidentally thrown there, ingeniously arranged 
so as to give the unsophisticated stranger at once a startling 
idea of the immense wealth of the company’s mines. Several 
gentlemen, dressed in the height of fashion, mostly headed by 
a venerable president-looking individual, are seated at their 
respective desks, the old gentleman occupying the private 
office in an enclosure. Whenever a stranger enters the office, 
all is bustle and business. You see enormous ledgers, stock- 
books, checks, and letters ready to be handed down at a mo¬ 
ment’s notice ; errand-boys and clerks appear and disappear 
rapidly (of course some bringing in heavy orders for shares of 
stock), and the superficial observer is impressed with the extent 
and importance of the business. The President, after some 
minutes’ delay, admits you to his sanctum, and, with a most 
winning way and benevolent condescension, explains to you 
the enormous income that will be made by the Company after 


21 


all the machines that have been sent out are put to work. 

Just then the Cashier hurriedly appears, and holding up the 

* 

bank-book to the President in such an ingenious way as to let 
you, too, see the large balance in favor of the Company, asks, 
in audible whisper, of course, if there are any more deposits 
to be made, the shares of the Company being all sold with the 
exception of a few odd shares, which, however, have been 
spoken for by some banking house, and will be sold next day. 
Few gentlemen, I believe, left the office without having 
purchased the few odd shares as a great bargain, and after 
some time they have found, to their great mortification, that 
the beautifully engraved certificates were the fancy represen¬ 
tatives of some “ wild-cat ” company. Of course the fash¬ 
ionable, uninterested friend, who took you to see the Elephant, 
gets a good commission, and is ever ready, should you meet 
him again, to tell you with woful countenance, that he , too , 
has lost heavily. 

Can we wonder, my friends, that our capitalists become 
shy and adverse to mining enterprises ? As one bubble after 
the other bursts, and the blissful ignorance of the companies • 
becomes known, we cannot blame anybody for holding back 
and asking for better information. 

When this pernicious, wild, and speculative excitement 
shall have died away, Gold-mining will be carried on as a 
regular business, depending not from the sale of shares of 
stock, and the ups and downs of the stock-market, but from 
its own products. 

Knowledge is spreading rapidly. The well-managed 
Mining-School in this city, and other private institutions (we 
have enough costly and corrupt government institutions, and 
think a Mining bureau a superfluity), will soon make their 
healthful influence felt in our mining regions. They well 
deserve the thanks and encouragement of the nation. 


22 


■ Let us return to our subject, Gold , and examine into the 

various systems used for extracting Gold from its ores. 

« - 

The various methods of working Gold ores can be divided 
into three classes, the mechanical, the chemical, and the 
mixed, combining the use of both methods. 

The mechanical method is certainly the simplest, and con¬ 
sists in crushing the ore to powder, by means of stamps or 
crushing-machines, and in extracting the Gold by means of 
amalgamating the precious metal with Quicksilver or Mercury. 
The more perfect the crushing and pulverizing process, the 
better, of course, is also the result obtained by the amalgama¬ 
tion. The crushing of ore is mostly done by the well-known 
old-fashioned stamp-mills. Some use steam or compressed 
air stamps; some adopt Whelpley and Storers centrifugal 
crusher and pulverizer, all of which seem to be improvements 
on the old stamp-mill, and certainly work well where they are 
in good hands and connected with machine shops and foun¬ 
dries. A new crusher (Wagner’s Patent) is now on exhibi¬ 
tion in this city, and works as well as any other I have yet 
* seen. The principal feature of this machine is the ingenious 
manner of crushing the ore by attrition; this is by rubbing the 
one piece of the stone with the other. I have seen four hun¬ 
dred pounds of hard quartzose Mexican Silver ore pulverized 
in eighteen minutes’ time to a powder so fine that most could 
pass through a No. 100 sieve. It weighs about four tons, and 
is very simple and compact in its construction. 

The old amalgamating system of. running the pulverized 
ore with water over amalgamated Copper plates is now grad¬ 
ually giving way to more perfect, though more complicated 
methods. Some run the ore into variously constructed pans, 
where, with assistance of heated water, a more perfect me¬ 
chanical mixture of the ore with the Mercury is obtained. 
This is more especially the case since Professor Henry Wurts, 


23 

of this city, has made the interesting discovery that the addi¬ 
tion of a small portion of Sodium metal to the Mercury 
increases the affinity of the Gold for the amalgam ; in most 
cases a considerably increased yield of Gold has thereby been 
obtained. The Frey burgh barrel, as well as Wykoff’s process 
of boiling the ore with Salt Water and Mercury, whereby 
some of the Sulphurets are decomposed, have, when carefully 
worked, given good results. Another, the “ Staats Amalga¬ 
mator,” treats the pulverized ore in a closed and heated revolv¬ 
ing iron boiler, with Steam and Mercury (in vapor form), 
whereby also very favorable results are obtained. I beg to 
mention here my own recently-invented Gold Extractor, where¬ 
by in twenty-four hours ten toils of tailings or pulverized ore 
can be worked by one man at a cost not exceeding fifty cents 
per ton. One of these machines (engine and boiler 6 hp. not 
included) can be made for one thousand dollars. The cost of 
amalgamating by the most ordinary method is about one dol¬ 
lar per ton. 

My Gold Extractor has one great advantage over others, 
and this is that no handling of plates nor separate distillation 
is required, the same all being done automatically. The 
retort is connected with the Mercury-bath in such way that 
the amalgam can be run into the retort and the Gold obtained 
without disturbing the operation by distillation in vacuum. 
A very efficient chemical agent assists in decomposing the 
Sulphvrets. 

We will now take up another system of treating the Gold 
ores, — the chemical method. We will subdivide it into the 
wet and dry, or fire treatment. The wet method we will call 
that by which the Gold is extracted from the ore in the form 
of an aqueous solution, the so-called Chlorine process. As, 
however, this treatment requires mostly a previous roasting 


24 


* 




of the ore, we will give at first to this interesting topic some 
attention. 

We have, in the first part of this pamphlet, shown that 
when Sulphurets in powder form are treated with Mercury 
the Gold was very imperfectly amalgamated, and could not all 
be extracted, only a comparatively small amount of the pre¬ 
cious metal uniting with the Mercury ; and that a perfect and 
careful roasting of the ore is required, as well as also a con¬ 
densation of the resulting vapors. I studied carefully the 
various processes in use, such as Keith’s, Whelpley and 
Storer’s, Dr. Hagan’s, Crosby and Thompson’s, Dr. Ott’s 
Kyason’s, and several others, all of which are said to give 
perfect satisfaction. We will only give to them a rapid glance 
without comments. 

The furnaces of Messrs. Whelpley and Storer in Boston 
have been described in most of our mining journals ; they cer¬ 
tainly look as if they could do some good work when properly 

managed. The ore, finely pulverized in their centrifugal 

% 

crushing and pulverizing machine, is blown, together with 
charcoal-powder, down a vertical shaft or tower, the gases 
condensed, and then treated for the different metals. Keith 
oxidizes the pulverized Sulphurets by air in an upward or 
horizontal direction. Crosby and Thompson do the same in 
a revolving retort; they condense most of the volatile pro¬ 
ducts. (I learned lately that they get from the condensed 
smoke as much Gold as they extract from the roasted ore.) 

A very neat arrangement for roasting has been patented, 

and is now being tested in Washington, D. C., by Dr. Adolph 

Ott, of this city. The Sulphurets pass successively through 

• v 

three separate superposed furnaces, in which automatic stirrers 
keep the ore in motion, and cause it to fall from one oven 
into the other, receiving three successive treatments, by which 
the ore is fully decomposed. The lighter metals, Zinc, Anti- 


25 


mony, Arsenic, and Bismuth are condensed in separate cham¬ 
bers, and the Sulphurous gases subjected to a spray before they 
are allowed to escape through the chimney. The desulphur¬ 
ized ore is then moistened by steam, and placed into a large 
tank, where it is treated with Oxychlorine Gas , which rapidly 
converts the present Gold into a soluble salt, the Terchloride of 
Gold Au Cl 3 which is leached out afterwards, either by pres¬ 
sure or by a centrifugal machine. The solution is then treated 
with Sulphate of Iron, or other precipitant, and the pure Gold 
taken from it as a dark brown powder. This is quite an im¬ 
provement on Prof. Plattner’s successful chlorination process, 
and shows that the originator understands what he is about. 
This process is also adapted for the treatment of Silver ores. 

Dr. Hagan! s desulphurizing process with Hydrogen Gas and 
Carbonic Oxide and Acid, produced by previous decomposi¬ 
tion of steam by carbon, is, as I learn* worked quite suc¬ 
cessfully for two years past in both Grasse Valley, Nevada 
Co., California, and Plymouth Ledge, in the same State. 
The Eureka or Ryason process is also said to work well in 
the Mariposa State in California. In this process, I learn, the 
desintegration, desulphurization, and extraction of Gold by 
amalgam are all produced by the action of heated Steam and 
Mercury vapor on the ore while in a closed vessel, and the 
tailings run over a peculiarly constructed shacking table, so 
as to concentrate all the amalgam. 

We will now pass finally to another system, the smelting 
method. When a rich Gold ore is heated in a reverberatory or 
other furnace, and an appropriate material as flux added, 
the ore melts with it to a liquid mass , in which the specifi¬ 
cally heavy. Gold will collect, melt, and sink to the bottom. 
Soda, Lime, Oxides of Iron have been extensively used, and 
some to great advantage. By my experiments with the 
so-called Stevens Flux , the residuum from the Cryolite when 


4 


26 


worked for Soda, I have been brought to the new idea that 
Gold must exist in nature as a Silicate of the Oxide of Gold 
chemically combined, for, by treating the same ore with other 
agents (fluxes that do not fully decompose Silica), I could not 
obtain the same results. 

This Stevens Flux is superior to the natural Fluorspar, 
because it contains free Oxyfluorine Gas, which has been 
absorbed by Lime in a similar way as Chlorine is taken up by 
it in the Bleaching Powder, hence its greater efficiency. 

The Fluorine has such affinity for the Silica that it leaves 
the Calcium, drives off the Oxygen, and combines with the 
Silicium to form Fluor Silicium and Fluosilicic Acid. The 
Calcium takes up the Oxygen and forms Lime. 

I have lately seen some astonishing results produced by the 
use of this Flux with Nova Scotia and Georgian ores. 

Mr. H. G. Hubert, of this city, has recently patented a 
system of furnaces, in which he uses a mixture of flux and 
ore as continuous lining of the furnaces (either cupola or 
reverberatory) with an impervious carbon-bottom. This sys¬ 
tem cannot fail to come into use when this peculiar method 
of smelting shall have been better known and appreciated. 

From the foregoing pages you will see that I have taken 
some pains to keep posted; I may add that during the last 
three years I have visited many mines, mills, and metal¬ 
lurgy establishments, and have made numerous experiments 
in my own laboratory. Taking all points, the defects as well 
as advantages of the afore-mentioned processes, into consid¬ 
eration, I have followed an entirely distinct road to arrive 
at long-desired results, — the extraction of all the Gold, with 
most advantageous utilization of the refuse. 

By a series of new processes, recently secured by Letters 
Patent, I can not only obtain a complete solution of the 
quartzose ores in water , but also a complete chemical decompo - 


27 


sition of the Silica itself so as to eliminate all that Gold that 
has hitherto been lost , because I believe that it exists in the 
Quartz in chemical combination. 

The best feature, however, and that which distinguishes this 
process from the old Quartz dissolving processes, is that the Hy¬ 
drate of Silica which I obtain (having no alkali), and which 
I receive as refuse, can be used for something better than for 
adulterating soap, and is worth, at least, one dollar a gallon, 
if sold only for a fire , water , and weather-proof paint , to say 

y 

nothing of its use in the manufacture of cast (not compressed) 
flint-marble in the shape of statuary, fountains, mantels, tables, 
monuments, floors, and ornaments of all kinds. 

There are numerous other processes in existence, and I 
shall take pleasure in mentioning them in a future larger 
publication on this subject after my return from an informa¬ 
tion trip to Europe. 

I cannot close without mentioning the merits of my es¬ 
teemed friend, Professor Benjamin Hardinge, of this city. 
This gentleman, by nature gifted with a truly We’bsterian 
memory and versatility of conversation, of most industrious 
habits and extraordinary perseverance, coupled with an irre¬ 
pressible fondness for anecdote and good-humor, has been 
the first to dissolve a large quantity of Quartz in water 
(1853-1857). The improvements which I have since made 
enable me not simply to dissolve, but to chemically decom¬ 
pose the siliceous ores. To the facilities for study and experi¬ 
ment which my friend has afforded me during the last twelve 
years, I am greatly indebted for what I have learned, and- 
desire, from my whole heart, that he may find the due reward 
for his long years’ labor. X have now combined my efforts 
with the long and varied experience of my esteemed friend, 
and look forward to the time when we shall be able to estab¬ 
lish the full value of our combined processes. 


A. L. FLEURY’S AND BENJAMIN HARDINGE’S COMBINED PRO* 
CESSES FOR WORKING GOLD ORES, AND USING 
THE LIQUID SILICA IN THE ARTS. 


The four American Patents, in which an Interest is offered, 
cover the following operations : — 

1. Complete desulphurization of Pyrites and Metallic 

Sulphurets. 

2. The Extraction of Gold and Silver from desulphu¬ 

rized ores or tailings by a new system of amal¬ 
gamation. 

3. The Solution and chemical Decomposition of the 

Quartzose Gold ores in the wet way, and without 
the use of either Soda or Potassa, by an entirely 
new process. 

4. The utilization of the refuse material for fireproof 

Porcelain paint, floors, pavements, and all kinds 
of ornamental Stone and Marble work. 

5. The manufacture of Sulphide of Silicium and Hy¬ 

drate of Silica with its many uses either made 
from sand, silicates, or quartz, and utilizing the 
Sulphur obtained by the Desulphurization of the 
Sulphurets. 

We will consider the advantages of these processes over 
all others now in use, and speak: — 

1. Of the System of Desulphurization. — In our combined 
process we desulphurize the ores in a complete manner, be- 



29 


cause we firstly bring the ground Sulpburets in close and 
most intimate contact with Carbon and Hydrogen , whereby 
the various complex sulphur combinations are broken up into 
more simple compounds , and are, when the ore is treated with 
alternate jets of air and steam , made much more ready to give 
off all the Sulphur, while the Gold is kept back with the Car¬ 
bon. 

2. The Extraction of Gold by amalgamation is performed 
by passing, by hydrostatic pressure , the pulverized ore, after it 
has either been treated with chemicals, or been desulphurized^ 
in contact with hot water , and thoroughly stirred, through a 
heated bath of Mercury , bringing thereby the water as well as 
every particle of ore into close contact with the Mercury. We 
use no Copper-plates , and have our apparatus so arranged that 
the Mercury that carries the Gold flows by its own weight into 
a retort, where, by a simple vacuum arrangement, the Mercury 
is distilled back again , from whence it came, and the Gold and 
Silver are left in the retort. This is all done automatically 
and without additional cost. One machine capable of treat¬ 
ing 10 tons of ore per day. with only one man (at a cost of 
50 cents per ton), can be constructed for $1,000. A. portable 
machine connected with a five horse power engine, with a ca¬ 
pacity to work 10 tons of tailings per day, can be made for 
$ 2 , 000 . 

3. The new Quartz dissolving process differs from all others 
in several distinct features: a. We use neither Soda nor Po- 

tassa. b. We do not only liquidize the Quartz in water , but 

* 

decompose chemically the Silica as well as Silicates , and thereby 
liberate not only the free Gold , but get also that which in many 
ores is chemically combined and locked up in the refractory 
matrix, c. The refuse , the liquid , from which, by passing it 
through my amalgamator, we first abstract all the Gold is not 
thrown away , but utilized by Mr. Hardinge in various ways. 


30 


One ton of Quartz yields about 900 gallons of a Hydrate of 
Silica, which, when mixed properly with Oxide of Zinc, or 
other similar materials, forms with them a cheap and fire¬ 
proof Porcelain Paint, and replaces Linseed Oil or Spirits of 
Turpentine. This alone, vnthout mentioning the adaptability 
of this liquid for the manufacture of ornamental Flint Marble, 
by casting the liquid, mixed with sand and proper crystalliz¬ 
ing agents, into moulds like Plaster of Paris, gives to the Hy¬ 
drate of Silica a value of at least $1 per gallon. The 
profit derived from the sale of this article is by far greater 
than the cost of treating the Quartz, and if we take into con¬ 
sideration the facility with which select Quartz can be shipped 
to Boston and New York from Nova Scotia and the Atlantic 
coast, and the demand for Fire, Water, and Rot-proof Paint 
and moulded Stones, Statuary, Fountains, Floors, Roofs, Pave¬ 
ments, etc., we cannot but feel confident of the success of this 
our enterprise. 

4. The treatment of pure Silica by the last-named, Sul¬ 
phide of Silicium-process, for the purpose of obtaining a pure 

r 

Quartz solution, a Hydrate of Silica, without alkali whatever 
(the water supplanting the base), has still another and very 
valuable advantage, lor by it all the Sulphur that is ejected 
by the desulphurization of the Sulphurets is therein utilized. 

From this very condensed statement, it can be seen that 
these combined processes show: 1 . Great Economy , because 
nothing is lost; all the refuse is made valuable. 

2. Great saving of time and labor. 

3. Effectiveness and increased yield of precious metals over 
and above other processes, because, as the Silica that holds 
the Gold either in fine diffusion or chemical combination is 
in this process completely decomposed, all tiie Gold can be 
extracted. 


31 


4. An unprecedented Profit. The utilization of the hydrat¬ 
ed Silica, as well as of all the Oxides, Vapors, etc., can clear a 
large profit, and reduce the expense of extracting the Gold 
from a ton of ore (which will cost about $10 a ton) actually 
to less than nothing, for the sale of the liquid from the 
working of one ton of ore can scarcely bring less than $900 ! 
What business , we ask , can exhibit such revenue ? 



We are now desirous to introduce these processes into 

m 

practical use, and for that purpose we offer an interest in the 
above-named Patents and Inventions on liberal terms. For 
further information, address either Benjamin Hardinge, New 
York , or, A. L. Fleury, 60 Sudbury St ., Boston. 




